'\" te
.\" Copyright (c) 1998, Sun Microsystems, Inc.  All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
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.TH DI_CHILD_NODE 3DEVINFO "Dec 1, 1998"
.SH NAME
di_child_node, di_parent_node, di_sibling_node, di_drv_first_node,
di_drv_next_node \- libdevinfo node traversal functions
.SH SYNOPSIS
.LP
.nf
\fBcc\fR [ \fIflag\fR... ] \fIfile\fR... \fB-ldevinfo\fR [ \fIlibrary\fR... ]
#include <libdevinfo.h>

\fBdi_node_t\fR \fBdi_child_node\fR(\fBdi_node_t\fR \fInode\fR);
.fi

.LP
.nf
\fBdi_node_t\fR \fBdi_parent_node\fR(\fBdi_node_t\fR \fInode\fR);
.fi

.LP
.nf
\fBdi_node_t\fR \fBdi_sibling_node\fR(\fBdi_node_t\fR \fInode\fR);
.fi

.LP
.nf
\fBdi_node_t\fR \fBdi_drv_first_node\fR(\fBconst char *\fR\fIdrv_name\fR, \fBdi_node_t\fR \fIroot\fR);
.fi

.LP
.nf
\fBdi_node_t\fR \fBdi_drv_next_node\fR(\fBdi_node_t\fR \fInode\fR);
.fi

.SH PARAMETERS
.sp
.ne 2
.na
\fB\fIdrv_name\fR\fR
.ad
.RS 12n
The name of the driver of interest.
.RE

.sp
.ne 2
.na
\fB\fInode\fR\fR
.ad
.RS 12n
A  handle to any node in the snapshot.
.RE

.sp
.ne 2
.na
\fB\fIroot\fR\fR
.ad
.RS 12n
The handle of the root node for the snapshot returned by
\fBdi_init\fR(3DEVINFO).
.RE

.SH DESCRIPTION
.sp
.LP
The kernel device configuration data may be viewed in two ways, either as a
tree of device  configuration nodes or as a  list of nodes associated with each
driver. In the tree view, each node may contain references to  its parent, the
next sibling in a list of siblings, and the first child of a list of children.
In the per-driver view, each node contains a reference to the next node
associated with the same driver. Both views are captured in the snapshot, and
the interfaces are provided for node  access.
.sp
.LP
The \fBdi_child_node()\fR function obtains a handle to the first child of
\fInode\fR. If no child node exists in the snapshot, \fBDI_NODE_NIL\fR is
returned and \fIerrno\fR is set to \fBENXIO\fR or \fBENOTSUP\fR.
.sp
.LP
The \fBdi_parent_node()\fR function obtains a handle to the parent node of
\fInode\fR. If no parent node exists in the snapshot, \fBDI_NODE_NIL\fR is
returned and \fIerrno\fR is set to \fBENXIO\fR or \fBENOTSUP\fR.
.sp
.LP
The \fBdi_sibling_node()\fR function obtains a handle to the next sibling node
of \fInode\fR. If no next sibling  node exists in the snapshot,
\fBDI_NODE_NIL\fR is returned and \fIerrno\fR is set to \fBENXIO\fR or
\fBENOTSUP\fR.
.sp
.LP
The \fBdi_drv_first_node()\fR function obtains a handle to the first node
associated with the driver specified by \fBdrv_name\fR. If there is no such
driver, \fBDI_NODE_NIL\fR is returned with \fIerrno\fR is set to \fBEINVAL\fR.
If the driver exists but there is no node associated with this driver,
\fBDI_NODE_NIL\fR is  returned and \fIerrno\fR is set to \fBENXIO\fR or
\fBENOTSUP\fR.
.sp
.LP
The \fBdi_drv_next_node()\fR function returns a handle to the next node bound
to the same driver. If no more nodes exist, \fBDI_NODE_NIL\fR is returned.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, a handle is returned. Otherwise,  \fBDI_NODE_NIL\fR
is returned and \fIerrno\fR is set to indicate the error.
.SH ERRORS
.sp
.LP
These functions will fail if:
.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 11n
The argument is invalid.
.RE

.sp
.ne 2
.na
\fB\fBENXIO\fR\fR
.ad
.RS 11n
The requested node does not exist.
.RE

.sp
.ne 2
.na
\fB\fBENOTSUP\fR\fR
.ad
.RS 11n
The node was not found in the snapshot, but it may exist in the kernel. This
error may occur if the snapshot contains a partial device tree.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7)  for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Evolving
_
MT-Level	Safe
.TE

.SH SEE ALSO
.sp
.LP
.BR di_init (3DEVINFO),
.BR libdevinfo (3LIB),
.BR attributes (7)
.sp
.LP
\fIWriting Device Drivers\fR
